1. Field of the Invention
This invention relates to a camera having a function of recording data such as a date, time or the like on a film loaded in the camera together with an image of a subject to be photographed, and more particularly, to an auto-focusing and auto-winding camera capable of effectively performing data recording in a consecutive photographing operation including exposing, focusing and shutter releasing.
2. Description of the Prior Art
There have heretofore been developed a number of auto-focusing cameras having a function of recording data such as a date, time or various photographing data on a film loaded in a camera body while taking a photograph.
Some types of principal mechanisms in the camera such as iris-shutter operating means and automatic focusing means have been proposed to date. For example, one of these has been earlier proposed by the inventor of this invention. (Japanese Patent Application Public Disclosure SHO No. 61-110123)
On the other hand, one version of a data recording device for recording data such as a date and time on a film is disclosed in U.S. Pat. No. 4,327,979.
Briefly stated, the data recording may be carried out within the period of time from shutter releasing to completion of photographing so that the data such as a date and time can be recorded. Nevertheless, the data recording which may sound like easy cannot easily be carried out in actual. In a date recording system in an ordinary automatic camera, which has light emitting means such as photodiode segments, the average time required for data recording is generally about 60 milliseconds. This data recording time is longer than that required for shutter releasing when the shutter opening-closing operation is effected at 1/60 sec., i.e. approximately 17 milliseconds. Compared with the time required for auto-focusing or auto-exposing, it is considerably longer. From the viewpoint of the efficiency of the existing light emitting means and the need for miniaturization and portability of a camera, for the present, the aforesaid time required for data recording (60 milliseconds) cannot be reduced.
How the data recording operation should be executed in the consecutive photographing operation including the automatic distance-measurement for focusing, automatic brightness-measurement, automatic focal-point determination, shutter releasing, etc. is a problem to be solved from the standpoint of the aforementioned needs of the automatic camera with a data recording function.
There have, been two methods of effecting the data recording, i.e. the pre-recording method and the post-recording method. In the pre-recording method, the data recording operation is carried out prior to the consecutive photographing operation including the focusing and exposing. The data recording which is effected after the consecutive photographing operation is designated as the post-recording method.
As one example of the pre-recording method, there has been proposed a data recording device for cameras in the aforementioned U.S. Pat. No. 4,327,979. This prior art device affects the data recording operation at an early stage of automatic focusing movement preceding the consecutive photographing operation including shutter releasing. Therefore, the data recording operation which is carried out before the consecutive photographing operation causes shutter releasing to be delayed. As a consequence, this method has suffered from inefficiency in that the time required for one photographing shot is lengthened.
In addition, if the prior art data recording device is constructed so that the data recording operation can be effected at the time of pressing a shutter release button in order for the shortage of photographing time, the data is printed on the film immediately after pressing the shutter release button. This entails a disadvantage in that once the shutter release button is pressed, the photographing operation cannot be called for even before the shutter is released or even when an exposure measuring circuit which is generally operated at the time of depressing the shutter release button detects an underexposure state.
Also, in a camera of the type in which data recording is performed upon completion of film winding as proposed by Japanese Patent Application Public Disclosure SHO No. 62-14630, the photographing operation cannot be canceled en route.
In the post-recording method described above in which the data recording operation is effected with the closing movement of the shutter after the opening of the shutter for forming an aperture is completed, the film winding cannot be performed immediately after the completion of shutter opening-closing. Accordingly, if the film winding is carried out in the data recording operation, a data image is printed on the film in a streaming manner.
Either of the methods requires a prolonged time for data recording and is unfit for automatic cameras.
There are also known data recording devices (cf. Japanese Patent Application Public Disclosures SHO No. 55-93135; SHO No. 55-98730; SHO No. 56-14227; SHO No. 56-77834; SHO No. 56-83729; SHO No. 56-109328; and SHO No. 56-132321). However, nothing in these prior art references discloses a data recording device capable of efficiently effecting data recording in the course of a consecutive photographing operation consisting of focusing, aperture determining and shutter releasing.